Evaporator, feed-water heater, and the like



Jame 24 1924. I

I H. c. DAVIS EVAPORATOR, FEED WATER HEATER, AND THE Filed Jan. 7, 1920 3 Sheets- Sheet 1 WITNESS:

ATTORNEYS,

' H. c. DAVIS EVAPORATOB, FEED WATER HEATER, AND THE LIKE Jame 24 1924.

. H. c. DAVIS EVAPORATOR, FEED WATER HEATER, AND THE LIKE Filed Jan. '7, 1920 WITNESS:

:5 Sheets-Sheet s INVENTOR. 0, M" BY E I ATTORNEYS.

Fatent He .24, was.

HOWARD DAVIS, OF ELIZABETH, NEW

JERSEY, Assrenon .ro AMERICAN EQUIPIVIEN'I .GORPORATIQN, A CORPORATION OF DELAWARE.

EVAPORATOR, FEED-WATER HEATER, AND THE E.

Application filed January To all whom it may concern:

, Be it known that I, HOWARD G. DAVIS, a citizen of the United States, residin at Elizabeth, in, the county of Union and tate of New Jersey, have invented certain new and useful Improvements in Evaporators, Feed-Water Heaters, and the like, of which the following is a full, clear, and exact description.

My invention relates to evaporators, feed water heaters and the like, one of the objects of the invention being to provide an improved construction of, and method of mounting, the heating coils whereby the coils are made interchangeable and reversible, and are rendered easily accessible for removal or repairs, without disturbance of the other coils, and whereby they may be connected to the feeder and discharge pipes in such a manner that any one or more of the coils may be removed without affecting th operation of the device with the remaining coils.

A further object of the invention is to provide a heating coil which has a maximum of heating surface in a minimum of space, is free from sharp turns and has both of its terminals at its periphery.

A further ob ect is to provide means for preventing vibration, sagging and consequent chafing of the coils one on another, when assembled. a

A further object is to provide a multiple coil unit in which the temperature in each coil can be separately regulated as desired under a constant steam' pressure in the supply pipe.

A further ob ect 18 to provide a device of this kind which, when used as an eva orator, will keep the formation of scale own to aminimum.

Other objects and advantages will be apparent from the following description and the novel features of my invention will be particularly pointed out in the claims.

In thedrawings:

Fig. 1 isa front elevation of an evaporator embodying my invention;

Fig. 2 is a vertical central sectional view of the same;

Fig. 3 is an elevation on an enlarged scale of the evaporator shell or casing with the closure plate or cover removed;

7, 1920. :Serial No. 349,985.

*sFig. 4 is a top plan view of the evaporator with the vapor dome removed;

Fig. 5 is a horizontal section ofthe same,

Fig. 6 is a'detail sectional view of the coupling between one of the. headers and a terminal of one of thecoils, and

Fig. 7 is a partial sectional elevation through one of the headers and a few of the nipples.

The main shell or casing 1 may be of any suitable shape. It has an opening in its side wall, for access to the interior, which is normally covered by a door or closure 2 removably attached thereto, as by bolts 3. Upon opposite sides of the casing 1, adjacent the side edges of the closure, and extending parallel therewith for substantially the length of the casing, are headers or conduits 4 and 5, which are referably cast integral with th casing. The casing is divided into a plurality of compartments or chambers by a series of partitions or bafile plates 6 which extend forwardly from the rear wall and alternately from opposite sides of the casing nearly across the interior thereof. A series of ribs 7 ion the inner face of the door or closure 2 are in line-with and form an ex- Atension of the baflle plates 6 and extend the chambers or compartments entirely to the front of the casing. Due to the fact that the baflie plates 6 extend from each side alternately nearly across the casing, each chamber or compartment communicates with the adjoining chambers at opposite ends. That is, the passages between the chambers or compartments are not in alignment but are arranged in. staggered relation, thereby forming a tortuous ascending passage through the casing.

Disposed within each chamber is a. heating unit & which comprises a double coil of peculiar construction. It is made up of two sections, the convolutions of each section lying in the same plane with each other but in a plane parallel to those of the adjacent section. In forming the double coil the from which the same is produced is t spirally inwardly from its periphe to form one section, is then bent downwar y or leterally from a point ad'acent the center of the section to the plane 0 the adjoinin section, and is then bent s irally outward in the same direction to t e periphery to arm the 1. rious coils or heating units.

second section. The terminals 9 and 10 of the coil are thus located at the perlphery thereof and when the coil is in place m the casing 1 said terminals lie at points ad acent the opposite side edges of the door or closure 2. All sharp bends in the c011 are avoided by this construction, and the coils are rendered reversible and interchangeable. Both sections of the coils are substantially rallel with the bafile or partitionplates 6.

no terminal 9 of each coil is removably connected to the header 4 by any? suitable coupling 11 and the other terminal 10' 1s similarly connected to the other header 5. The coupling 11 may conveniently comprise a nipple 12 threaded at one end into an openm 13in the header and communicating wit the passage therein, and having its other end threaded to receive a threaded cap or nut 14 through the end of which the coil terminal passes. The end of the terminal is flared and held against the beveled end of the nipple by a ferrule 15 which is in turn pressed toward the end of the nipple 12 by the end wall of the nut 14. This provides a suitable joint which permits of quick and'easy attachment or detachment, between the coil terminal and header, by the application of the nut to or its removal from the nipple. The nuts 14 are easily accessible from the front of the casing when the door or closure 2 is removed so that each heating unit or coil can be removed or inserted without disturbance of or hindrance by the other coils or units.

The nipples 12 which connect the various coil terminals 10 to the header 5 may have openings which vary in size, so that the amount of steam admitted to any one unit or coil is dependent upon the size of the opening in the particular nipple used. The nipples may be arranged in any desired order with respect to the size of the passages.

therein, along the length of the header, but I preferably arrange them with openings or passages varying from a minimum at the top to a maximum at the bottom of the header. Steam is supplied to header 5 through an inlet 16 and passes therefrom into the va- A steam trap (not shown) is connected to the outlet end 17 of the header 4. When a solution such as sea water, is evaporated, the solution becomes more dense, the denser portion settles to the bottom, and steam at a higher temperature is thus necessary to evaporate the liquid at "the bottom of the casing than is necessary for the less dense liquid in the upper portion of the casing. The temperature of the steam passing through the coils 8'varies with its pressure, and greater expansion takes place in the steam which passes into the coils through the smaller openings in the stems 12 than in the coils supplied through the larger openings. Thus essence to the coils 8 by the steam therein varies progressively from a minimum at the top to a maximum at the bottom so that the body of water or liquid being evaporated in the easing is kept at a temperature substantially at the evaporation point throughout. The passages through the nipples 12 from the feeding header 5 may be uniform in size if desired but I have found the varying sizes specified to be a more efficient) and preferable construction. By varying the nipples 12 according to the size of the passages therethough, the heat imparted to each coil or unit can be selectively varied as desired.

When certain liquids such as sea water are evaporated, a scale tends to collect or form on they heating surfacesand on the inner walls of the casing. The formation of this scale is greatest at some distance from the point where the fresh liquid is supplied to the casing. To overcome the same, I propose to supply the feed water or liquid alternately at different points in the casing, so that the fresh liquid entering the casing at any point will tend to dissolve off any scale which may have formed While the liquid was being supplied at another point in the casing. The liquid is drawn or blown ofi' at intervals when the density exceeds a certain amount and fresh liquid supplied, or the blowoff may be a gradual one. This removal of the denser liquid carries off the scale-forming substances contained therein. In the construction illustrated, I supply the liquid to be evaporated through a pipe 18 to a vertical pipe 19 extending along the casing and connecting with a plurality of the chambers formed by the bafiie or partition plates 6. The connections shown are with the top and bottom chambers. In the vertical pipe 19 I provide a pair of valves 20 and 21, to determine through which chamber in the casing the feeding or fresh liquid is to be supplied. Leading from the lowermost chamber is a blow off outlet 22 which may be left partly open, or be opened to greater extents at intervals to carry off the liquid with the high percentage of scale forming substances therein. I prefer to close valve 21 and open valve 20 for a short time and then close valve 20 and open valve 21 to supply the fresh liquid alternately to the bottom and top chambers for the purpose described. When rapid ebullition of a liquid occurs a considerable amount of liquid is entrained in the vapor and carried along with it. Unless some means of removing this entrained liquid be provided the liquid of condensation will not be a pure distillate. I therefore provide a steam or vapor dome 23 on top of the evaporator casing the same having a curved conduit 24 therein for deflecting the vapor or steam against the walls of the dome a short distance above the bottom thereof and permitting the entrained liquid to settle out and be collected at the bottom of the dome, from which it is conducted by a pipe or conduit 25 to one of the chambers below the liquid level in the casing; At the upper discharge end of the dome is a conduit 26 which is curved oppositely to conduit 24 so that a somewhat tortuous path through the dome [must be traversed by the vapor or .steam before it passes oif to the condenser (not shown). The steam or vapor dome being of larger volume, or area,than the pas-- sages 24 and 26 will cause a slower movement of the vapor therethrough, so that any entrained liquid may settle to the bottom and be conducted back to the evaporator casing, while the oppositely curved conduit ends (24 and 26) willprevent the direct passage of the vapor and entrained liquid. A suitable water or liquid gauge 27 is connected between the dome and the lower portion of the evaporator by connections 28 and 29, so that the level of the liquid in the evaporator casing will be indicated at all times.

Inasmuch as the evaporator will be commonly used adjacent running machinery, it will be subject to vibrations therefrom. In order to prevent vibration and consequent chafing of one portion of a coil 8 on another portion, as well as to prevent sagging or deformation of the coil due to its weight, I propose to provide a flat strap 30 along each of the outside faces of thecoil unit and another strap 31 between the two sections of eachcoil, and clamp these straps together by any suitable means such as bolts 32, to hold the coils against relative movement.

In use, the heating steam is supplied to the header 5 through a connection 16 from which it passes to all the coils, and the water of condensation passes out through the header 4 and connection 17 to a steam trap (not shown). The liquid to be evaporated is supplied through pipe 18 to the vertical branch pipe 19. By operation of the valves 20 and 21, the liquid may be alternately supplied to the top and bottom chambers to keep the scale formation to a fminimum. When the density of the liquid in the easing rises beyond a certain amount, the liquid is blown ofi through outlet 22 at the bottom of the'casing in order to carry off the concentrated solution containing a high per centage of scale forming substances. If desired, of course, the blowofi may be a gradual, continuous one instead of an intermittent complete one. The liquid as it is evaporated passes upwardly through the tortuous passage from one chamber or compartment to another until it finally passes out through the dome of the condenser. The passage of the vapor through the varlous chambers, as described, increases the emciency and efiectiveness of the evaporator.

It will be according to my invention, the coils 8 are reversible, and the terminals 9 and 10 are at the periphery of the coil Where they are readily accessible when the door or closure 2 is removed, so that the coil units may be separately removed or repaired without disturbance of, or hindrance from, the other coils. By removing a coil and supplying blank caps to the stems where the removed coil was originally connected the function or use of the evaporator may be continued with only a slight reduction in capacity until a new coil can be secured or the "old one repaired. This is of especial im 01'- tance when the evaporator is used on s 'ps because in such cases new or repair parts are not always quickly available.

While I have described any invention with reference to its use as an evaporator it is obviously not confined to this use. In fact I propose to employ it in the construction of feed water heaters and condensers, and for the heating and cooling of liquids generally. The coils 8 have been described as being designed to receive the heating medium, steam, with the liquid to be treated surrounding said coils, but it is obvious that either a heating or a cooling medium may be used in the coils, and that a heating or cooling medium may be used on the outside of the coils with the liquid to be treated passing through the coils.

I claim:

1. In an apparatus of the character described a casing, said casing having a removable side wall acting as a closure therefor, a header disposed along the casing adjacent each side of and parallel with the closure, a plurality of coil units within the casin'g each extending between and connecting said headers, bafie plates disposed between adjacent coil units and extending alternately from opposite sides of the casing nearly across the same, whereby the passages between the different chambers formed by the baflie plates t are staggered with relation to one another, and plates carried by the closure abutting against the baflie plates of the casing to complete the chambers entirely to the closure.

2. In an apparatus ofthe character described, a casing, said casing having a removable side wall acting as a closure therefor, a header disposed along the casing adjacent'each side of and parallel with the closure, a plurality of substantially parallel coil units connecting said headers theconnections between a plurality of the units and one of said headers having openings of difi'erent sizes.

3. In an apparatus of the character described, a casing, said casin-g'having a removable side wall actin as a closure therefor, a header disposed a ong the caslng adobserved that in a constructionjacent each side of and parallel with the I closure, a plurality --of substantiaIl paraland one of said headers ,4 for, a pluralityof plates extending across the interior of said cas ng, ribs. carried by the closureand co-operating with said partitions to form a series of communicating chambers, heating units in said chambers, and-means for at will supplying a fluid to said casing. through any of aplurality of said chambers. I '5. In an apparatus of the character described, acasing, a plurality of heating units in said casing, aplurality of baflie plates arranged in said casing between certain of the units, and means forsupplying a fluid to be heated alternately to different portions of the casing,

6, In an apparatus ofthe character described acasing, said casing having .a removable,- side wall acting as .a closure therefor, a p lurality -o.-plates extending across theinteriorj oisaid-- casing, ribs carried by eases-a supported by the walls thereof, platescarried by the closure and co-operating with the otherplates to form a plurality of chambers within said casing, coil units within said chambers, connections leading from the exterior of the casing to said coil units and connections leading to a plurality of said chambers.

8. In 'an apparatus of the character described, a casing havin a chamber therein coi1s passing throu the chamber for heating its contents, an a plurality of connections opening into said casing at separated points for supplying a fluid to be heated to said casing at: more than one point.

Inwitness whereof, Ihereunto subscribe Q y i n e-.-

nown o. DAVIS. 

